checksum ref tus#347

Author: pushpush

lib/browser/extensions/checksum.ts

@@ -0,0 +1,41 @@
+export type AlgorithmsTypes = 'SHA-1' | 'SHA-256' | 'SHA-384' | 'SHA-512'
+
+export interface ChecksumInterface {
+  algorithm: AlgorithmIdentifier;
+  getHexDigest(data: ArrayBuffer): Promise<string>;
+}
+
+class Checksum implements ChecksumInterface {
+  static supportedAlgorithms: AlgorithmsTypes[] = ['SHA-1', 'SHA-256', 'SHA-384', 'SHA-512'];
+  public algorithm: AlgorithmIdentifier;
+
+  constructor(algo: AlgorithmsTypes = 'SHA-256') {
+    // Checking support for crypto on the browser
+    if (!crypto) {
+      throw new Error(`tus: this browser does not support checksum`)
+    } else if (!Checksum.supportedAlgorithms.includes(algo)) {
+      throw new Error(
+        `tus: unsupported checksumAlgo provided. Supported values are : ${Checksum.supportedAlgorithms.join(
+          ',',
+        )}`,
+      )
+    } else {
+      this.algorithm = algo
+    }
+  }
+
+  getHexDigest = async (data: ArrayBuffer) => {
+    try {
+      const hashBuffer = await crypto.subtle.digest(this.algorithm, data)
+      const hashArray = Array.from(new Uint8Array(hashBuffer)) // convert buffer to byte array
+      const hashHex = hashArray
+        .map((b) => b.toString(16).padStart(2, '0'))
+        .join('') // convert bytes to hex string
+      return hashHex
+    } catch (err) {
+      throw new Error('tus: could not compute checksum for integrity check ' + err)
+    }
+  };
+}
+
+export default Checksum

lib/browser/index.ts

@@ -8,12 +8,14 @@ import { BrowserFileReader } from './BrowserFileReader.js'
 import { XHRHttpStack as DefaultHttpStack } from './XHRHttpStack.js'
 import { fingerprint } from './fileSignature.js'
 import { WebStorageUrlStorage, canStoreURLs } from './urlStorage.js'
+import Checksum from './extensions/checksum.js'
 
 const defaultOptions = {
   ...baseDefaultOptions,
   httpStack: new DefaultHttpStack(),
   fileReader: new BrowserFileReader(),
   urlStorage: canStoreURLs ? new WebStorageUrlStorage() : new NoopUrlStorage(),
+  checksum: new Checksum(),
   fingerprint,
 }
 

lib/options.ts

@@ -1,6 +1,7 @@
 import type { ReadStream } from 'node:fs'
 import type { Readable } from 'node:stream'
 import type { DetailedError } from './DetailedError.js'
+import {AlgorithmsTypes, ChecksumInterface} from "./browser/extensions/checksum.js";
 
 export const PROTOCOL_TUS_V1 = 'tus-v1'
 export const PROTOCOL_IETF_DRAFT_03 = 'ietf-draft-03'
@@ -61,10 +62,12 @@ export interface UploadOptions {
   removeFingerprintOnSuccess: boolean
   uploadLengthDeferred: boolean
   uploadDataDuringCreation: boolean
+  checksumAlgorithm?: AlgorithmsTypes
 
   urlStorage: UrlStorage
   fileReader: FileReader
   httpStack: HttpStack
+  checksum?: ChecksumInterface
 
   protocol: typeof PROTOCOL_TUS_V1 | typeof PROTOCOL_IETF_DRAFT_03 | typeof PROTOCOL_IETF_DRAFT_05
 }
@@ -83,6 +86,7 @@ export interface UrlStorage {
   addUpload(fingerprint: string, upload: PreviousUpload): Promise<string | undefined>
 }
 
+
 export interface PreviousUpload {
   size: number | null
   metadata: { [key: string]: string }

lib/upload.ts

@@ -16,6 +16,7 @@ import {
   type UploadOptions,
 } from './options.js'
 import { uuid } from './uuid.js'
+import Checksum from "./browser/extensions/checksum.js";
 
 export const defaultOptions = {
   endpoint: undefined,
@@ -47,10 +48,12 @@ export const defaultOptions = {
   removeFingerprintOnSuccess: false,
   uploadLengthDeferred: false,
   uploadDataDuringCreation: false,
+  checksumAlgo: undefined,
 
   urlStorage: undefined,
   fileReader: undefined,
   httpStack: undefined,
+  checksum: undefined,
 
   protocol: PROTOCOL_TUS_V1 as UploadOptions['protocol'],
 }
@@ -104,6 +107,8 @@ export class BaseUpload {
   // parts, if the parallelUploads option is used.
   private _parallelUploadUrls?: string[]
 
+  private _checksum ?: Checksum
+
   constructor(file: UploadInput, options: UploadOptions) {
     // Warn about removed options from previous versions
     if ('resume' in options) {
@@ -585,7 +590,10 @@ export class BaseUpload {
     if (!this.options.endpoint) {
       throw new Error('tus: unable to create upload because no endpoint is provided')
     }
-
+    if (this.options.checksumAlgorithm) {
+      // @ts-ignore
+      this._checksum = new this.options.checksum(this.options.checksumAlgorithm)
+    }
     const req = this._openRequest('POST', this.options.endpoint)
 
     if (this.options.uploadLengthDeferred) {
@@ -882,6 +890,16 @@ export class BaseUpload {
     ) {
       req.setHeader('Upload-Complete', done ? '?1' : '?0')
     }
+
+    if (this.options.checksumAlgorithm) {
+      if (this.options.checksum) {
+        // @ts-ignore
+        let chunkBuffer = await value.arrayBuffer()
+        let hash = this.options.checksum.getHexDigest(chunkBuffer);
+        req.setHeader('Upload-Checksum', `${this.options.checksum.algorithm} ${hash}`)
+      }
+    }
+
     this._emitProgress(this._offset, this._size)
     return await this._sendRequest(req, value)
   }